Changes to ghc

Changes to ghc:
commit 98b6756b09194352aa2ccfbb624992150a7a3520
Author: Richard Eisenberg <eir@cis.upenn.edu>
Date:   Wed Feb 26 10:17:45 2014 -0500

    Fix #8807.

    It turns out that the enhanced repPred function in DsMeta assumed
    that the head of any constraint would be a tycon. This assumption
    is false. Happily, the solution involved *deleting* code. I
    just removed repPred in favor of repTy, and added the HsEqTy case
    to repTy, where it should be anyway.